This application claims benefit of Japanese Applications No. 2002-229058 filed in Japan on Aug. 6, 2002, No. 2002-171622 filed in Japan on June 12, No. 2002-242251 filed in Japan on Aug. 22, 2002, the contents of which are incorporated by this reference.
1. Field of the Invention
The present invention relates to the structure of a lens shutter, a macro-lens adapter, a camera capable of mounting a macro-lens adapter, and a camera having a negative LCD in front of a taking lens.
2. Related Art Statement
In conventional lens shutters each using a set of sectors driven so as to open and close, in order to open and close the shutter, it is necessary to move the sectors once so as to open and then immediately reverse them so as to close.
In order to realize high-speed operation in the above-mentioned conventional lens shutter, Japanese Examined Utility Model Registration Application Publication No. 45-26780 discloses a lens shutter using two sets of rotatable sectors, first set of sectors serving as opening sectors and second set of sectors serving as closing sectors. In this lens shutter, in the shutter opening and closing operation, the opening sectors are moved in only one direction of opening the sectors and the closing sectors are moved in only one direction of closing the sectors. Accordingly, the foregoing reverse operation is not needed. There is no time lag caused by the reverse operation. Thus, the operation of the shutter can be performed at high speed.
Japanese Unexamined Patent Application Publication No. 6-43520 discloses an aperture mechanism having a plurality of sectors rotated in order to form and close an aperture. In the aperture mechanism, the center of pivot of each sector is pivotably supported by the corresponding supporting pin of a cover plate. A sliding pin disposed at one end of each sector is slidably fitted into the corresponding long hole of a sector plate which is rotated. In each sector, the supporting pin and the sliding pin are arranged so as to sandwich an aperture therebetween. The sector plate is rotated to pivot the sectors, thus changing the size of the aperture.
In macro photography, the image of a subject is enlarged and is then photographed. Hitherto, in macro photographing using a camera which cannot perform macro photography, a mechanism for attaching a macro lens as an auxiliary lens for macro photography, namely, a macro-lens adapter is attached in front of a taking lens of the camera. Light rays from a subject are allowed to pass through the attached macro-lens adapter, thus performing macro photography.
In general cameras each having a barrier, when the barrier is opened, the camera enters operating mode (the camera is turned on). When the barrier is closed, the camera enters non-operating mode (the camera is turned off). As mentioned above, in many cases, the opening and closing operation of the barrier is synchronized with the turn-on/off of the camera.
Conventional cameras include a camera having a detachable lens barrel. The lens barrel has therein a photographing optical system comprising a plurality of lenses and a drive mechanism for the lenses. The lens barrel is detachably mounted on a camera body having various components therein. Further, a member such as a lens cap for protecting the surface of the lens and blocking out unnecessary light that enters the camera through a gap between a lens fixing frame and the lens can be attached to the front surface of the lens barrel.
According to the present invention, there is provided a lens shutter system including: a shutter blade for opening and closing an opening through which light rays for photography pass; and a drive member for applying a driving force to open and close the shutter blade.
In the lens shutter system, the shutter blade is driven by the drive member, the shutter blade pivots about a first axis parallel to the optical axis of the light rays in one direction to perform the opening operation, and further, the shutter blade pivots about a second axis parallel to the optical axis of the light rays in the same direction as the one direction to perform the closing operation, the second axis being different from the first axis.
According to the present invention, there is provided another lens shutter system including: shutter blades serving as members for opening and closing an opening through which light rays for photography pass, each shutter blade being pivoted on the central point of first pivot and being pivoted on the central point of second pivot, each shutter blade having an edge segment constituting the edge of an aperture through which the light rays pass, the edge segment being formed between the central point of the first pivot and the central point of the second pivot, the central point of the first pivot and the central point of the second pivot being arranged in each shutter blade so as to sandwich the light rays therebetween; a drive member for applying a driving force to open and close the shutter blades.
In the lens shutter system, the shutter blades are driven by the drive member, the shutter blades are pivoted on the respective central points of the first pivot in one direction to form the aperture using the edge segments, and further, the shutter blades are pivoted on the respective central points of the second pivot in the same direction as the one direction to close the aperture.
According to the present invention, there is provided further another lens shutter system including: shutter blades serving as members for opening and closing an opening through which light rays for photography pass, each shutter blade being pivoted on the central point of first pivot and being pivoted on the central point of second pivot, each shutter blade having an edge segment constituting the edge of an aperture through which the light rays pass, the edge segment being formed between the central point of the first pivot and the central point of the second pivot, the central point of the first pivot and the central point of the second pivot being arranged on the outward of the light rays for photography respectively so as to sandwich the light rays therebetween; and a drive member for applying a driving force to open and close the shutter blades.
In the lens shutter system, the shutter blades are driven by the drive member, while the respective central points of the second pivot are being rotated about the optical axis in one direction, the shutter blades are pivoted on the respective central points of the first pivot in the same direction as the one direction to form the aperture using the edge segments, and while the respective central points of the first pivot are being rotated about the optical axis in the same direction as the one direction, the shutter blades are pivoted on the respective central points of the second pivot in the same direction as the one direction to close the aperture.
According to the present invention, there is provided still another lens shutter system including: shutter blades each having an edge segment constituting the edge of an aperture through which light rays for photography pass, each shutter blade being pivoted on the central point of first pivot and being pivoted on the central point of second pivot, each edge segment being formed between the central point of the first pivot and the central point of the second pivot, the central point of the first pivot and the central point of the second pivot being arranged on the outward of the light rays for photography respectively so as to sandwich the light rays therebetween; a first rotation drive member for rotating the central points of the second pivot about the optical axis in one direction and simultaneously pivoting the shutter blades on the respective central points of the first pivot in the same direction as the one direction to form the aperture using the edge segments; and a second rotation drive member for rotating the central points of the first pivot about the optical axis in the same direction as the one direction and simultaneously pivoting the shutter blades on the respective central points of the second pivot in the same direction as the one direction to close the aperture.
In the lens shutter system, the first rotation drive member pivots the shutter blades in the one direction to form the aperture and the second rotation drive member pivots the shutter blades in the same direction as the one direction to close the aperture.
According to the present invention, there is provided a camera capable of mounting a macro-lens adapter with a barrier which is slidable between a position to cover the surface of a macro lens used for enlarging a subject in macro photography and a position to expose the surface of the macro lens. The camera includes a taking lens and an operating-mode setting unit for switching the mode of the camera between operating mode and non-operating mode in accordance with the position of the slid barrier. The macro-lens adapter can be attached in front of the taking lens.
According to the present invention, there is provided a macro-lens adapter including: a macro lens for enlarging a subject in macro photography; and a barrier which is slidable between a position to cover the surface of the macro lens and a position to expose the surface of the macro lens.
According to the present invention, there is provided a camera including: a negative LCD which is disposed in front of a taking lens and which blocks out light in non-photographing mode; and a control unit for controlling the negative LCD so that the negative LCD allows light to pass through at least upon exposure.
According to the present invention, there is provided another camera including: a negative LCD which is disposed in front of a taking lens and which blocks out light in non-photographing mode; and a control unit for controlling the negative LCD so that the negative LCD allows light to pass through upon focusing and exposure.
Other features and advantages of the present invention will become more apparent from the following description.